Hi Ed,
I have had the same problem, and probably the better
idea might be control the resist volume you deposit on
the wafer, and start with a fast acceleration to get
the excess of resist go away and don´t stain the back
side.
 If it doesn´t work, you always can clean the
splashback with a solvent, like acetone or any other.

 Good look!

 Eowin Rohan


--- Edward Sebesta 
skrev:

> I have an MTS 8800 with splashback problems, that is
> photo resist
> redopositing on to the back side of the wafers.
>
> I have check the exhaust and made sure it was the
> maximum. I have tried
> recipe modifications with lower acceleration for the
> resist spin step.
> These are the standard causes for the problem.
>
> I would like to know the following.
>
> 1. Does anyone have a contact for persons
> manufacturing retrofit resist
> spin bowls?
>
> 2. Does anyone have a fix for this or suggestions.